伦敦横贯铁路（2016年更名为伊丽莎白线）是欧洲最大的工程项目。它是伦敦交通局投资计划的重要组成部分，也是 50 年来对交通系统最大的扩建项目。

该项目包括一条横跨大伦敦、全长118公里的东西向铁路线，西起雷丁和希思罗，东至申菲尔德和阿比伍德。

自 2009 年以来，Dextra 已在 20 多个包裹上提供了超过 600,000 个 Griptec 连接，其中包括：

• 利物浦街
• 帕丁顿
• 邦德街
• 金丝雀码头
• 皇家橡树门户网站
• 布丁厂巷

Griptec 连接器已用于 D-Wall（垂直和水平连接）、柱和桩（垂直连接）。

Crossrail 的部分路段预计将逐步开始运营，预计于 2019 年 12 月全面竣工。

The Rio de Janeiro Line 4 is a subway line. It is part elevated and part underground (2 segments). The line has been planned to open for the 2016 Rio de Janeiro Summer Olympics.

Dextra has been involved since between 2013 and 2015 in the design, engineering and supply of four large FRP Soft Eyes for the station entry/exit points. Those Soft-Eyes were the first ever delivered in the South American continent.

在 D-Wall 施工之前，Dextra 设计 FRP 笼时会考虑 TBM 的尺寸、误差范围、土壤力和更多设计参数。

Thanks to the properties of FRP material, Tunnel Boring Machines cut through the D-Wall in a minimum time, saving time on schedule and ensuring the perfect condition of the TBM’s head. The time factor is especially important in humid environments such as Rio to limit the water entry into the station excavations.

On this project, Dextra also supplied Rolltec Rebar Couplers, used as vertical connections in the station diaphragm walls as vertical connectors to reconnect cages.

Couplers were also used horizontally to provide a reconnection point for slabs (at station level and at the surface) in the D-Walls.

Nagpur, the second capital of Maharashtra and one of the fastest developing city in India is witnessing major growth in terms of Infrastructure. The development encompasses primarily the connectivity, of which Metro rail becomes a major part.

Incepted in 2016, the metro project is being a subject of acclaimed discussion for its speed of execution and the quality of construction.

Within the city boundaries, it requires the highest standards of safety considerations including the seismic analysis of structure in service life.

Project Requirement

The fast track project has typical structure for its Line 1 alignment, where the viaducts are supporting 2 levels of pathways, lower one for NH-7 and upper one for the metro rail. As the impact loading is a big concern due to train movement.
Being the stretch of always busy traffic, a solution was required which does not have to revise the existing design. Plus a major concern was the impact on speed of the otherwise fast moving project. The issue was concerning to all the stakeholders especially the GC for the project, who were looking to maintain the agility as well as find a sustainable solution.

Solution

Dextra Introduced Shear Key Bars for the priority section allowing the structure to neutralize the seismic forces. This not only helped the contractor to get the work done faster, but also enabled the client to go for the trial run earlier than expected.

The Doha Metro is a rapid transportation system, designed as an integral component to the larger Qatar rail network. This country wide mega-scale infrastructural project consists of 300km of rail and 100 stations. The rail network to reduce traffic congestion, and to connect the people of Qatar with the rest of the GCC region. At the city scale, currently under construction, the metro is projected to be operational by the end of 2019. It will serve Doha and its surrounding suburbs with stations located in all major nodes of the metropolis. Doha Metro will be operating both at grade and below grade, with the majority of the metro project being underground. Complex tunneling and soil retaining solutions by Dextra were utilized in the construction of this project.

Glass Fiber Reinforced Polymers (GFRP) as Tie-back anchors to retain soil

To eliminate concerns of encroachment, and obstacle for future construction projects, the Diaphragm Wall (D-Wall) at Al Sadd C-Ring Station were post-tensioned anchored with ASTEC Active Active Anchor. These high performance, fully cut-able GFRP anchors were chosen by ALSYJ JV contractors and the D-Wall anchors of choice. This innovative solution was chosen because it can be cut by Tunnel Boring Machines (TBM) or standard excavation equipment, it also doesn’t need to be removed from the ground even in temporary applications. For Al Sadd C-Ring Station 7,113 strands for GFRP rebars were used to make approximately 700 ground retaining anchors used in the D-WALL around that station.

The Second Ho Chi Minh City Environmental Sanitation Project consists of the construction of interceptor that will convey the wastewater collected from the Nhiêu Lộc-Thị Nghè Canal and District 2 areas of Ho Chi Minh City to the treatment plant.

Dextra has been involved in the construction of the large underground system by supplying 40 Soft-Eyes to assist in the tunnel breakthroughs.

The cuttable Glass Fiber Reinforced Polymer (GFRP) Soft-Eyes were applied to reinforce 21 shafts, allowing the penetration by the Tunnel Boring Machine (TBM) without the need of removing steel reinforcement and without the risk to damage the TBM’s head.

With its completion, planned to be in 2022, the wastewater services in HCMC will have a considerably more sustainable nature, and will be remembered as the first big step toward the alleviation of the environmental and sanitation issues of the Country.

Doha Metro Phase 1 is Qatar’s mega infrastructure project of three metro lines with a total length of 164 km. The first phase involves the construction of red, green and gold lines and their major stations. It is a part of a US$36,000 million Doha Metro Rail Network Project, aiming to reduce the city’s road traffic congestion while facilitating the connection between Qatar and other Gulf countries.

The required completion period of this project is extremely short: with excavation starting in mid-2013 and operations expected by 2019. With the timeline of the project being constrained, high innovative solutions are required to complete the building of underground structures in a minimal amount of time.

Dextra’s FRP Active Anchors as temporary tie-backs in retaining walls

Composite materials have been used for over 20 years as temporary reinforcement in concrete structures. In Doha metro phase 1, both Dextra’s post-tensions carbon-FRP (CFRP) Active Anchors and glass-FRP (GFRP) Active Anchors have been used in retaining walls. When used as temporary tie-backs, CFRP material is offering the most advanced technical solution thanks to its superior properties in tensile, creep and durability, while the GFRP Anchors offers a cost-effective solution without technical compromise.

GFRP anchors can advantageously replace steel removable anchors to prevent encroachment of neighboring plots. This is why nowadays, GFRP anchors account for more than 90% of the FRP anchors installed in the region.

For the first phase of the Doha Metro Rail Network project, Dextra has been supplying 150 CFRP Active Anchors and 700 GFRP Active Anchors to date.

ASTEC Soft-Eye for a better penetration of TBMs

Dextra’s ASTEC Soft-Eyes is a unique technology using cut-able GFRP reinforcement as a replacement of conventional steel rebars. Since 1996, this solution has become a standard concept in the design of shafts and subway stations. More than 10 sets of Dextra’s ASTEC Soft-Eyes have been supplied and used in Doha Metro construction project as per May 2018.

To reduce traffic congestion on Mexico – Toluca highway, as well as to ease connections between both cities, the Secreatariat of Commuciations and Transportaion (SCT) is undergoing the construction of the new Mexico city areas’ 55.7-kilometer rail line. Aiming to be an environment-friendly project, the commuter rail line includes 4.7-kilometer double-tube tunnel in highly complex terrain and natural protected areas.

The new train will connect Toluca Valley to Mexico City, and will provide a service to an estimated 270,000 commuters. The line included 6 stations: 2 terminals (Zinacantepec and Observatorio) and 4 intermediate (Cristobal Colon, Metepec, Lerma, and Santa Fe). It will also be a backbone for Mexico City area’s regional and urban transport.

The construction being initiated in 2015, the railway is scheduled for completion in 2019.

Light and productive rebar coupler solution for the construction project

For the reinforcement of the railways concrete structures, Dextra supplied more than 100,000 Rolltec splices. The system is a practical and economic alternative to laps. Rolltec is also supported by one rebar preparation equipment, and only one man is needed to operate the machine.

Plus, thanks to the performance of our machines, the thread is ready in less than 30 seconds!
Moreover, with Rolltec system, the same type of coupler can be used for both standard and position applications, resulting in an optimized inventory of the project.

For more information about our projects in Latin America, contact our Panama Office.